comer



J. J. COMER.

TRANSMITTING APPARATUS.

APPLICATION FILED MAR.25. 19x4.

Patented June 3, 1919.

2 SHEETS-SHEET T.

F/&- 5

[N VENTOQ Wnwsssss ATTORNEY E STATES PATENT OFFICE.

JOHN J. COMER, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ENUNCIATOR COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TRANSMITTING APPARATUS.

Specification of Letters Patent.

Patented June 3, 1919.

T 0 all whom it may concern:

Be it known that I, Jonx J. Conan, a citizen of the United States of America, and resident of Chicago. Cook county, Illinois, have invented certain new and useful Improvements in Transmitting Apparatus, of which the following is a specification.

My invention relates to microphone transmitting apparatus in general.

My invention also relates to microphone transmitters adapted for use in connection with phonograph records. In devices of this cha 'acter the vibrating arm that controls the vibrations which directly affect the microphone should be properly insulated from vibrations through the solid material from the rest of the structure. so as to prevent undesirable tones from creeping into the sound when reproduced, thereby preserving the sound free from disagreeable tones and harshness. Further, the vibrating arm must be nicely balanced to reproduce freely and easily all vibrations gathered from the record. To obtain this'result I have balanced the diaphragm vibrating arm on points and clamped it in position by non-metallic spring material. The balancing points or trunnions and the clamping material in this instrument are located all in the same plane and parallel to the main diaphragms.

One of the objects of my invention is to provide an improved form of transmitter of this character for use in connection with records which require the needle to vibrate perpendicularly to the surface of the record, whether the record is of the cylinder or disk type.

Another object of my invention is to provide an improved construction and arrangement to enable the record to advance the microphone bodily in a more efficient and satisfactory manner than heretofore.

It is also an object of my invention to provide certain details and features of improvement tending to increase the general efficiency and serviceability of a transmitter of the above character.

The means for accomplishing the above and other useful ends are hereinafter set forth and claimed.

In the accompanying drawings Figure l is a front elevation of my apparatus.

Fig. 2 is a cross section view of the same.

Fig. 3 is a. detail bottom view of the instrument showing the vibrating arm that controls the diaphragms and showing the mounting member.

Fig. l is a sectional view taken on line H (Fig. 3). i

Fig. 5 is a detail bottom view of the stylus.

Fi s. 6 and 7 show the front and back faces of the instrument.

Fig. 8 is a diagrammatic illustration of the circuits.

Rezerring to the drawings it will be seen that the main supporting arm 5 *arries the terminal 6. To this terminal the frame ring 11 is secured by means of screws 6 and the bracket 7 in which latter they are embedded. The terminal 6 and the bracket 7 are separated by suitable washers 7'. To this terminal 6 there is )ivoted the weight 10 through the medium of the pin 10'. The transmitting apparatus consists of disks 8 and 9, between which is located the frame ring 11. The diaphragms l2 and 13 are like wise mounted between these disks by means of the rubber or asbestos rings or washers ll, in a manner which will be readily understood by reference to F ig. 2 of the drawings. There is a microphone transmitter located upon the outside of each of the disks 8 and 9. Each of these transmitters are separated from the respective disks by means of the felt packing 15. The two microphones are similar in construction and consist of the diaphragms- 16 and 16 upon opposite sides of which are mounted bodies of granular carbon 17. This granular material covers the central portion of the diaphragm, while the marginal portions of the diaphragm are surrounded by a restricted air space formed by the clamping plates 37 and 38, 39 and 40. The parts are held together by means of three through-bolts 19. These bolts are surrounded by a felt packing 20. By this construction, that is, by the employment of the felt packing 15 between the disks 8 and 9 and the microphone transmitter and by means of the felt packing about the through-bolt 19 I provide a very efficient construction. as by this means it is practically impossible for the diaphragm 16 of the microphone transmitters to be vibrated by any foreign or extraneous vibrations through the solid structure of the instrument. The use of the felt packing provides a very loose and flexible construction between these parts, so thatv the vibrations of the diaphragm are entirely caused by the vibrations received through the air from the diaphragms 12 and 13.

A vibrating arm 21 is mounted between the diaphragms 12 and 13, one end of which is secured thereto. This arm is provided at the lowest end with a branch 21 at right angles to the plane of the diaphragms. A bearing plate 23 is mounted on the reproducing arm, which bearing plate pivots on two trunnion points 21- substantially in a plane with the arm 21 and parallel to the diaphragms. In order to hold the bearing plate upon these trunnions I provide hearing screws 27, which pass through the insulating washers 29 of rubber or felt or other suitable insulating material. I thus avoid all metallic connections between the hearing plate and these bearing screws. These bearing screws being mounted in line with the trunnions 2% do not control or damp the vibrations of the diaphragm to any appreciable extent, but permitthe arm to vibrate freely on the trunnions and I find, however, that good results are obtained by partly controlling the arm by supplying a certain amount of tension thereto through the medium of the diaphragms to which the arm is connected. This is accomplished in the following manner:

A pin 30, threaded at both ends, is passed through the center .of the diaphragms 12 and 13, one end of the pin projecting on one side of the diaphragm 12 and the other end on the opposite side of the diaphragm 13. This pin also passes through a hole near the end of the arm. 21, as indicated in Fig. 2, and the arm 21 securely fastened thereto, as for example, by being soldered. Two nuts are screwed on each end of the pin, one on each side of the diaphragm, as shown in Fig. 2. These nuts are tightened against the diaphragms so as to clamp them and at the same time bend toward each other to create a tension for the purpose of controlling the arm 21. This pressure is produced by the nuts causing the diaphragm to present an approximately concave surface to each other and can be regulated so as to give the proper amount of control for the vibrating arm. After the proper tension has been given to the diaphragm the nuts may be fixed in any suitable manner, as already stated, as for example by using wax or some other composition. As has already been explained the projection 21 of the arm 21 is connected by a silk cord or other tension member 31 with the stylus 32. This stylus is provided with suitable pivot points 33, which project from a plate 31 fastened to the wei ht member 10. When the point of the stylus engages a record the point of the stylus is raised, thereby raising the weight member 10 and placing a tension in the cord 31. Under these conditions the vibrations which are communicated to the stylus are communicatcd to the pro ecting arm 21' and in turn through the arm 21 to the diaphragms 12 and 13. It will be seen that the terminal 6 is secured to the end of the arm 5 by means of screws insulated against vibration and it will be further seen that the weight 10 is prevented from falling below a certain limit by the screw 36, which in working position clears the weight 10. Further, it will be noted that the weight 10 is insulated from the rest of the structure by suitable vibration insulating medium 37.

\Vhile the instrument as a whole is clamped by the bolts 19. each side of the instrument is held together by still other bolts 11 and 42 (see Figs. 1, (3 and T). The bolts *1 are riveted to the ring 38 and project out through the front part of the iiistrument (see Fig. 1). The bolts 42 are riveted to the ring 39 and project out through the other plates to the back part of the instrument. One. of the bolts 11 is used as a terminal for the conductor 13 and for the line conductor 13'. which are connected through a lamp or other resistance to one terminal of the battery B. In a similar manner one of the bolts =12 is used as a terminal for the conductor 11 and the line conductor 4%, which are connected through a lamp or other resistance to the same terminal of the battery B. There is another terminal 15 in the front part of the instrument which is connected to the diaphragm 16 and to which there is connected a conductor l6 and to the opposite side of the battery. There is another terminal 47 in the back part of the instrument which is connected to the diaphragm 16 and to which there is connected a conductor 18 and to the same side of the battery as conductor 16. There is another terminal 19 in the front part of the instrument which is connected to the ring 37 and which acts as a terminal for the line conductor 50 and for the conductor 51, both of which run through a resistance to the same terminal of the battery as the other line conductors. There is another terminal 52 in the back part ofthe instrument connected to the ring 40 and to which the line conductor 53 is connected and also the conductor 51, both of which are connected to the same terminal of the battery as the other line conductors. \Vith the circuits as shown, it will be seen that the central diaphragm can be operated to send current variations over the two lines at the same time, one of which lines is inclicated by the conductors 43 and 50 and the other one by the conductors 53 and 14:. All of the plates which are in front of the plate 38 are secured together by the nuts on the terminal 11 and all of the plates in front of the plate 39 are secured together by the nuts on the terminal 42.

Referrin to the weight 10 carried on the arm 5 it W1 1 be observed that the insulation 37 is for another purpose also namely to act as a yielding joint between said weight and arm in order that the weight and arm may follow more easily in the path indicated or marked out by the record and travel more smoothly than heretofore and without the necessity of having a metal groove to cause the arm 5 'to advance with the record.

It will thus be seen that I have devised a new and very efficient and delicate mechanism in a transmitter adapted for use in connection with the hill and dale type of record.

What I claim as my invention is:

1. In an electric transmitter, a set of diaphragms arranged in parallel, a vibrating arm and means whereby the vibrations of said arm are transmitted to said diaphragms, microphone cells each comprising a vibrating member, one cell located on each side of said set of diaphragms, the vibrations of said diaphragms being pneumatically transmitted to said microphones, and a stylus with a tension member for transmitting the vibrations of the stylus to the vibrating arm and a weight for keeping said tension member under tension normally.

2. In an electric transmitter, a centrally located vibrating member, microphone cells, each comprising a diaphragm located one on each side of the central member, an electrode chamber surrounding the central portion of each of said diaphragms, and an air space surrounding the marginal portions of said diaphragms, a vibrating arm attached to said member, a stylus with a ten sion member for transmitting the vibrations of the stylus to the vibrating arm and a weight for keeping said tension member under tension normally, and a pneumatic medium for communicating the vibrations from the member to the diaphragm.

3. In an electric transmitter, a vibrating member, microphone cells associated with said member but insulated therefrom against vibrations from said member through the solid structure of, the instru-' ment, and a stylus with a tension member for transmitting the vibrations of the stylus to the vibrating member and a weight for keeping said tension member under tension normally, and a pneumatic medium for communicating the vibrations from the member to the microphone cells.

- 4. In an electric transmitter, a supporting member, a vibrating member, means for mechanically transmitting vibrations to said vibrating member, a microphone cell, the vibrating member and the cell mounted on said supporting member but insulated from each other and from the supporting member against the vibrations from each other and from the supporting member through the solid structure of'the instrument, said means comprising astylus with a tension membercfor transmitting the vibrations of the stylus to the vibratlng member and a weight for keeping said tension member under tension normally, and a pneumatic medium for communicating the vibrations from the member to the microphone cell.

5'. In an electric transmitter, a stylus, a pivot therefor permitting the stylus to vibrate in a plane perpendicular to the record, a controlling weight for the stylus on one side of the pivot, a vibrating arm, a tension member attached from the other end of the stylus to one end of the vibrating arm, said arm having the other end attached to a vibrating diaphragm whereby vibrations imparted to the stylus are imparted in turn to the vibrating diaphragm, microphones adjacent to said diaphragm and pneumatic means for communicating the vibrations of said diaphragm to said microphone, said vibrating arm and diaphragm being vibration insulated from the solid structure of the in strument.

6. In an electric transmitter, a stylus, a pivot therefor permitting the stylus to vibrate in a plane perpendicular to the record, a controlling weight for the stylus on one side of the pivot, a vibrating arm, a tension member attached from the other end of the stylus to one end of the vibrating arm, said arm having the other end attachedto a.

vibrating diaphragm whereby vibrations imparted to the stylus are imparted in turn to a the vibrating diaphragm, microphones adj acent to said diaphragm and pneumatic means for communicating the vibrations of said diaphragm to said microphone, said vibrating arm and diaphragm being vibration insulated from the solid structure of the instrument, said vibrating arm supported on trunnion points and held on said points by clamping means, the trunnion points and the points of en agement of the clamping means being located in the same plane and parallel to the diaphragm.

7. In an electric transmitter, a main diaphragm, a vibrating arm attached thereto, microphone cells each comprising an auxiliary vibrating diaphragm, one of said cells located on each side of said main diaphragm, the vibrations of said main diaphragm being pneumatically transmitted to said microphones, and a stylus with a tension member for transmitting the vibrations of the stylus to the vibrating arm and thence to the main vibrating diaphragm, and a weight for keeping said tension member under tension normally.

8. In an electric transmitter, a phonograph record, a stylus for engaging therewith, a frame for carrying the stylus, a pivoted arm for carrying the frame, a resilient member separating the stylus frame from the arm, means for movin the record and for causing the stylus to ollow the groove in the record and at the same time advance with the groove, the motion of the stylus being communicated to the pivoted am through the resilient member and a microphone controlled by said stylus.

9. In an electric transmitter, a phonograph record, a stylus for engaging there with, a frame for carrying the stylus, a pivoted arm for carrying the frame, a resilient member separating the stylus frame from the arm, means for moving the record and for causing the stylus to follow the roove in the record and at the same time a Vance with the groove, the motion of the stylus being communicated to the pivoted arm through the resilient member, and a microphone mounted on said moving arm and in connection with the said stylus, and means for causing the said stylus to operate said microphone.

10. In a combined electrical transmitter and phonograph, a stylus having motion in one plane, a microphone transmitter having a resilient frame and having a vibrating member connected with said stylus, said vibrating member subject to vibrate in a different plane, said transmitter having also microphone cells pneumatically controlled through the medium of said vibrating mem- 11. In a combined electrical transmitter and phonograph, a stylus having motion in one plane, a microphone transmitter having a resilient frame and having a vibrating member connected with said stylus, said vibrating member subject to vibrate in a different plane, said transmitter having also microphone cells pneumatically controlled through the medium of said vibrating member, said stylus and microphone transmitter all mounted on a pivoted arm, and means for moving the whole structure through the stylus.

Signed by me at Chicago, Illinois, this 19th day of March, 1914.

JOHN J. COMER. Witnesses:-

HUBERT W. KRAcKE, B. GARBER.

Copies of this patent may be obtained for five cents each, by addressing the "commissioner of Patents, Washington, D. c." 

